The proposed research should contribute to the understanding of axonal targeting in the nervous system (NS). Knowledge about this process could help in designing of somatic gene therapy in he NS, especially in some degenerative disorders and in mechanical damage to the NS. Molecular biology techniques (cDNA cloning. mRNA fingerprinting, sequencing, and sequence analysis) are to be used in conjunction with astrocyte culturing to find genes regionally expressed in population of astrocytes. Culture, purified astrocytes from various parts of neonatal rat brain will be used as a source of mRNA which will be analyzed by mRNA fingerprinting to find the differentially expressed cDNA clones in fetal rat brain cDNA libraries. The selected cDNA's will be sequenced and the sequences will be searched for clues about their function. If time allows it will be attempted to verify the functional importance of the differentially expressed cDNA's in anti-sense mRNA experiments with co-cultures of astrocytes and neurons.